Electronic device

Abstract

A load circuit operates by power supplied from a power supply apparatus. A capacitive element is connected in parallel with the load circuit. A switching element is connected between the power supply apparatus and the load circuit in series with the power supply apparatus and the load circuit. A monitor section monitors voltage of the capacitive element and is connected in parallel with the capacitive element. An inrush current control section changes resistance of the switching element on the basis of the voltage monitored by the monitor section in order to control inrush current that flows at the time of an electronic device being plugged into or unplugged from the power supply apparatus. A breaker circuit prevents electric charges stored by the capacitive element from flowing into the monitor section at the time of the electronic device being unplugged from the power supply apparatus.

What is claimed is: 
     
       1. An electronic device plugged into or unplugged from a first power supply apparatus, the electronic device comprising:
 a load circuit which operates by power supplied from the first power supply apparatus; 
 a capacitive element connected in parallel with the load circuit; 
 a switching element connected between the first power supply apparatus and the load circuit in series with the first power supply apparatus and the load circuit; 
 a monitor section which monitors voltage of the capacitive element and which is connected in parallel with the capacitive element; 
 an inrush current control section which changes resistance of the switching element on the basis of the voltage monitored by the monitor section in order to control inrush current that flows at the time of the electronic device being plugged into or unplugged from the first power supply apparatus; and 
 a breaker circuit which is a first rectifying element placed between the switching element and the monitor section and which prevents electric charges stored by the capacitive element from flowing into the monitor section at the time of the electronic device being unplugged from the first power supply apparatus. 
 
     
     
       2. The electronic device according to  claim 1 , wherein:
 the electronic device is plugged into or unplugged from a second power supply apparatus; and 
 the breaker circuit further includes a second rectifying element connected in series with the monitor section. 
 
     
     
       3. The electronic device according to  claim 1 , wherein when the voltage monitored by the monitor section is zero, the inrush current control section exercises control so as to make the resistance of the switching element infinite. 
     
     
       4. The electronic device according to  claim 1  further comprising:
 an on-off switch which controls an electric current that flows through the monitor section; and 
 an on-off switch control section which turns off the on-off switch at the time of the electronic device being unplugged from the first power supply apparatus. 
 
     
     
       5. An electronic device plugged into or unplugged from a power supply apparatus, the electronic device comprising:
 a load circuit which operates by power supplied from the power supply apparatus; 
 a capacitive element connected in parallel with the load circuit; 
 a switching element connected between the power supply apparatus and the load circuit in series with the power supply apparatus and the load circuit; 
 an inrush current control section which changes resistance of the switching element on the basis of voltage of the capacitive element in order to control inrush current that flows at the time of the electronic device being plugged into or unplugged from the power supply apparatus; 
 an operation control circuit which shuts off supply of power to the inrush current control section at the time of the electronic device being unplugged from the power supply apparatus; and 
 a breaker circuit which is a rectifying element placed between the switching element and the operation control circuit and which prevents electric charges stored by the capacitive element from flowing into the operation control circuit at the time of the electronic device being unplugged from the power supply apparatus.